The objective of this study is to determine the optimal geometrical features of a microdrill with the diameter of 0.11 mm. The optimal geometrical dominant features of a micro-drill have been determined by carrying out the optimization stress/displacement analysis of the Pro/Mechanica software so that the maximum stress von Mises of the micro-drill was minimal. Based on the verification of the drilling test, the mean total hits to breakage of the micro-drills, fabricated with the determined optimal geometrical features, was 16% more than that of the micro-drills fabricated with the original geometric parameters.